In order to optimize the performance of the liquid crystal display in the design of the existing driving circuits, the angle cutting function is added to achieve more uniformly display in the horizontal direction. Its working principle is: by the timing signal to control the thin film transistor-liquid crystal display, TFT-LCD and open the output terminal of the angle cutting voltage VGH to operate discharging, so that the waveform of the opened output terminal of the angle cutting voltage VGH that actually control the TFT-LCD is changed from constant voltage to a periodic sloping falling voltage.
As illustrated in FIG. 1, the structure in FIG. 1 is usually adapted in the conventional angle cutting circuit. By controlling the waveform of the square wave GVON and the resistance of the angle cutting resistor R, the waveform of the output terminal of angle cutting voltage VGH can be changed to achieve optimization purposes of the display. In the meantime, referring to FIG. 2, FIG. 2 is a waveform diagram illustrating the square wave GVON and the angle cutting resistor R. When the square wave GVON is in low electrical level, the constant voltage input by the input terminal VGHF is discharged, and the waveform becomes gate shaped VGH waveform wherein the time of the angle cutting can be decided by the time of the square wave GVON is in low electrical level, the rate of the angle cutting can be decided by the resistance of the angle cutting resistor R.
Since the difference of the operating modes of the liquid crystal display, the need of the best angle cutting waveform can be different. In other modes, such as the 3D functionality mode, the time of the angle cutting can be changed by controlling the variation of the waveform of the square wave output from the terminal of the sequence controlling T-con. But the angle cutting resistor R that influence the angle cutting rate cannot be adjusted, resulting in the best angle cutting waveform cannot be obtained in other modes.